Method for improving the flavor of coffee



5 etc.,

Patented Jan. 23,1940

METHOD FOR IMPROVING THE FLAVOR OF COFFEE Gwynne Evans, St. Louis, M0.-

N0 Drawing.

Application June 22', 1939',

- Serial No. 280,523

4 Claims.

This invention relates-to the treatment'of coffee and has for itsprimary object the provision of an improved method of preparing a batchof coffee berries to be subsequently roasted, ground, so that: theultimate' product will possess a substantially uniform flavor or tastethroughout said batch, irrespective of the use of varie ties of berriesof substantially different quality initially admixed to constitute saidbatch.

Practical experience has demonstrated that the success of commercialenterprises devoted to the sale of cofiees to the public depends essentially upon flavor or taste, and, it has been.

a common observation that where berries emanating from different sourcesand possessing their own differentiating characteristics are notsubjected to like preparatory treatment, the desired uniformity offlavor or present through the various portions of the mixture or batch.

Many attempts have been made to insure such uniformity, but inherentuncertain factors have operated thereagainst. Customarily, the bestpractice-has been to make careful selection of the berries obtained fromvarious fields, countries, or sources, and mix these after the mannerascertained to be capable of resulting in the desired blend, roast thesame to different degrees, and when the beverage has been prepared inthe customary fashion, subject the latter to what is known as the cuptest by abstracting and using the mixture from various portions or thebatch and relying on the tasters to conclude whether the desired flavoror taste has stances, been subjected to a greater or less degree ofroasting until approximately satisfactory results have beenaccomplished. Howeven when relying upon what was believed to be theadjusting or curing of the defects by varying the step of roasting,failure has frequently been met withbecause, while the "cup test" seemedto be satisfactory and, accordingly, a batch passed by inspection, otherportions of the batch would be found by the ultimate user to beobjecticnable. ing the growth of the various grades or kinds of coffeebrought together in the mixture'were ignored.

A good mixture which, under best conditions, would possess asatisfactory taste or flavor, may be illustrated as combining high gradeof Bourbon Santos (Brazilian cofiee) high altitude Medellin or,Manizales (Colombian coffees), and high taste is not assuredly,

This was because factors attendaltitude Mexicans or Guatemalas orKilimanjaro:

- (an African coffee).

Owing to the superior conditions under which Brazilian cofieeisgrown,and where the same is subjected to substantial irradiation by thenatural violetrays of the sun, that coffee will run wellto standard andmay be relied on quite fully at all times; and this is comparativelytrue of some of the other high altitude. coflees where, i

because of such altitudes, thatcofiee also is subjected tothe-beneficial influence of irradiation by said violet rays of the sun.However, such precise or relatively perfect conditions lendingthemselves to mixtures of coffee with resultant definite control oftaste, seldem prevail or persist. Adverse conditions continually arise,because some coffee in the blend has been affected by adverse cropconditions, too long exposure on docks, open warehouses or platformsorbecause of having been transported from its source to the. place of usein poor hulls (it being approximated that about sixty days is requiredfor coffee to be carried fromcoifee sources to the United States undermost favorable customary conditions) Humidity and other climaticconditions, exposure or lack of exposure of the coffee while awaitinshipment, storage, etc., also offer changing conditions affectingqualities in different lots of berries. All of these items, and others,constitute a hazard or risk, warning against simply mixing theberriesfrom the various sources, with the expectation that all portions of agiven batch will result in uniformity of taste characteristics.

The present invention embraces the taking of I been attain If not, theymixture haskin 1 different coifees in the condition in which they ing anicety of flavor and taste; also eliminating objectionable so-calledgreen or grassy ,flavor so often encountered. The latter constitutes aserious detriment to the sale of any, brand of coffee, even though theutmost care has been exercised in the blending thereof. As heretoforeinferred, this green or grassy taste of some of the coffee of a blendinevitably escapes the tests of the tasters, because, obviously, allcoffee going to make up the mixture or batch cannot possibly becup-tested or, in fact, tested in any other practical fashion.

With the foregoing understanding of conditions in mind, the preferredembodiment of my invention may be said to involve i timate mixing of theselected different coffee berries together and then subjecting theentire mixture or batch 5s believed that it acid in undue quantities, asan ingredient of cot-- the market and capable. of imparting ultra-violetrays-so thatall of the berries of the mixture or batch, inclusive ofthose that have in their natural growth been subjected to the naturalviolet rays of the sun, will be subjected to the influence. of theraysover and above all previously received, to the sun. V I r r ,Theinvention embraces the idea of giving all of the berries,notwithstanding their different sources of origin, the same orequivalent treatment, so that a desired'standard forthe whole isattained. n

It is estimated that ultra-violet rays are possibly as much as ten timesas strong as the rays of the sun to which the berries in their normalgrowthare'subniitted; so that by subjecting all .of the berries of themixture or batch to the ultra-violet rays for a sufficient period oftime, the berries of inferior quality are cured to a point beyond thecured state of the better-quality berries that have had more benefitfrom the sun in their normal growth, and thelatter are further treatedto the extent of the influence of the additional treatment by theultra-violet rays. Thereby, all of the berries will be brought to thestate of a. common, uniform, and desired standard, the result being acorrespondingly uniform taste or flavor throughout the entirebatch ormixture. 7

Although it is impossible to state the. exact chemical or other reactionor reformation that,

transpires throughout the batch, .it has been proven by tests that bythe treatment of the batch or mixed coffee berries of differentqualities by the'ultra-violet rays, an advantageous result is gainedthat has never previously been reached; namely, able excessive presenceof chlorogenic acid. It is the presence of chlorogenic fee berries, thatcauses a coffee beverage to possess the rancid, green, or grassy taste.A certain proportion of this acid ingredient appears to exert noobjectionable influence on the flavor of the coffee, but its presenceortaste quality beyond a given amount impairs the beverage so far as itsflavor or taste quality is concerned.

The ultra-violet ray treatment, asstated, of the entire batch or mixturesubstantially reduces this chlorogenic acid constituent and rids thefinal product free of the taste or flavor thereof.

In that aspect, the practice of the improved method thereof lends itselfto the attainment coffee berries of the predetermined uniform nicety, orstandard of taste or flavor quality of the product throughout; that is,irrespective of where any portion of the batch or mixture may beabstracted from the bulk or batch that has undergone the method oftreatment of the instant invention.

In practicing said invention, the appropriate emanating from thepreferred plantations or sources'selected, for instance as hereinaboveoutlined, are brought. together in any desired proportions andintimately mixed, for, example, utilizing the preferred coffee (as theBrazilian) as'the base or greater proportion, and the others (asColombian) in minor proportions, dependent'upon the taste or flavordesired; these intimately mixed coffees thus affording the batch to betreated.

While preferably and ordinarily this mixture or batch will comprise thecoffee berries for subg rea'ter or less extents, from the elimination ofobjectionl to a treatment of ultra-violet rays-for example,- through themedium of lamps, obtainable in jection to further treatment, it isappreciated that the additional treatment inother instances can besuccessfully pursued after grinding the mixture. Therefore, it will beunderstood that this pre-grinding modification of the preferred methodof the invention embodying the treatment of the whole berry is withinthe scope of the invention;

The next step will be, preferably, a spreading outof the mixture orbatch into a relatively thin layer formation, as distinguished from thegreater depth or density of the bulk or initially mixed batch, andfinally subjecting the spread-out coffee berries to the action ofultra-violet rays; in other words, irradiatingthe coffee throughout. Therays are applied to the coffee for a period preferably between four tosix minutes, the present practice being for substantially a five-minuteperiod, which is giving very satisfactory results. However, the range ofperiods of practical treatment is between a period of three and one-halfminutes as a minimum and a. period of six minutes as a useful maximum.In this connection a consideration to have in mind is that while thetreatment may be carried on even beyond the six-minute period to as highas thirty minutes, and in fact therebeyond, tests have proved that nosubstantial effect is had on the mixture of berries when 'undulyprolonging the treatment. ,It .appears that a treatment terminating atthe end of a six-minute period as just about the same result on theberries as a treatment carried beyondsuch six-minute period.

The foregoing observation is relevant, because the demonstration of thefact that there is no changed condition in the berries from,a prolongedtreatment by the ultra-violet rays'as compared to the effect on theberries at the end of a treatment fo'rsix minutes shows that-the berriesthat have initially received the better benefit from the natural violetrays of the sun, together with the berries that have receivedlessbeneflt in that regard, can, as a mixture, be additionally treatedby subjection to said ultra-violet rays to bring all berries of thebatch to a like or equivalent ultimate stage of treatment to obtain thepredetermined standard without causing any deleterious or harmfuleffects on those berries that theretofore had the best opportunity fortreatment by the natural rays of the sun.

A'batch'of the miscellaneous berries gathered from the differentoriginal sources, when irradiated according to the step of the methodincluding the application of the ultra-violet rays to the mixture forthe period stated-approximately six minutes-will reduce the chlorogenicacid content in the neighborhood of 30%; or, more specifically, in aninstance where the product with no light treatment originally contained9.7 chlorogenic acid, the same product when subjected to the lighttreatment for the six-minute period showed the chlorogenic acid to havebeen reduced to 6.4, a comparatively unobjectionable quantity so far asthe taste quality of the coffee is concerned.

uous one, that is, uninterruptedly for six minutes,

it is noted that in a test such as just referred to, the mixture wassubjected to repeated treatments by the ultra-violet rays for successiveperiods of two minutes each, aggregating a six-minute period. So, itmust be further understood that in, respect to periods of treatment, theinvention embraces the ultra-violet ray irradiation, whether 1stantially consisting in bringin together the application. of the lightbe continuous or intermittent, so long as the total period of treatmentis followed out.

After the desired treatment ready for roasting and grinding and use inbeverage form in the habitual manner.

While herein there is disclosed a practical and the preferred formermanner of practicing the method of the present invention, it will beclear that the invention is not to be restricted to specific detailsrecited, save as the same may be included in the hereto appended claims.

I claim: I l. The method of treating. a batch of coflee comprising amixture of coilee berries of subresultant product a, substantiallyuniform taste characteristic throughout the batch, the same a lot ofberries known to have been substantially exposed to natural violet raysof the sun and other berries known not to have had similar exposure orfor other reasons to be of relatively interior quality, intimatelymixing the two grades of berries, dispersing the mixture to present thesame in relatively thin layer formation, and subjecting said layer tothe influence of ultra-violet rays for a period of approximately 3% to 6minutes, thereby reducing any chlorogenic acid content to a negli--gible quantity and irradiating the entire batch impart to the resultantproduct a substantially oi the mixture or batch has been accomplished bythe irradiation method stated, the irradiated coflee berries arediflerent qualities to impart to the x the uniform taste characteristicthroughout the batch, the same consisting in intermittently mixing thediflerent lots of berries together and subjecting the same to theinfluence oi ultra-violet rays for a period of approximately sixminutes, to reduce any chlorogenic acid to a negligible quantity andirradiatethe entire batch to a degree whereby the whole will haveequivalent treatment by violet rays and coiIee abstracted anywhere fromthe batch will possess substantially identical taste.

3. The method of treating a batch of cofiee comprised of a mixture ofcoflee berries from diI- ferent sources, to impart to the resultantproduct a substantially uniform taste or flavor characteristicthroughout the entire batch, the same consisting in bringing togetherseveral lots of berries,

intermittently mixing the berries from the various lots, and subjectingthe intermixture to the influence of ultra-violet rays for approximatelyfive. minutes to additionally irradiate the berries that have receivedsubstantial treatment by the natural rays of the sun and to treat therelatively less cured berries to a point equal to said-additionaltreatment of said whereby the whole intermixture will ultimately havehad equivalent irradiation and cofiee abstracted anywhere substantiallyidentical taste. r

4. The method of treating a batch of coilee made up of miscellaneouslots of coffee berries some of which have been subjected to relativelysubstantial influence of the natural violet rays of the sun and othersof which have been grown under relatively less favorable conditions orhave become deteriorated, whereby there is imparted thereto a rancid orgreen taste, the same consisting in intermixing the berries of saidvarious qualities and sublectingQthe entire mixture to the influence ofultra-violet rays for a period sufli cieritly long to cure all of theberries throughout the whole batch for a period of 3V minutes.

GWYNNE EVANS..

first-mentioned berries,

from the batch will possess

